quux

Quux is a metasyntactic variable used in computer science as a placeholder name in example code and documentation. It commonly appears in sequences with foo, bar, baz and qux, where it stands in for values, functions, or modules during explanation or testing. Quux is not a language keyword or reserved word in standard programming languages; it is simply an identifier chosen to illustrate structure without implying meaning.

Origins and usage of quux are informal. It is part of the broader tradition of using nonsensical words as placeholders in programming culture, a practice that grew out of early programming communities in the 1960s and 1970s. The exact origin of quux is not precisely documented, and its position within the sequence of metasyntactic variables varies by author and language. Over time, quux has become a familiar fixture in many technical writings and teaching materials alongside foo, bar, baz, and qux.

In practice, quux is used to represent a variable, function, or module name in examples, tutorials, and explanations. Its semantics are defined solely by the surrounding code and context, and developers typically replace it with meaningful identifiers relevant to their domain when writing real software.

See also: metasyntactic variable; foo; bar; baz; qux.